The Targus Privacy Screen Filter was purchased for my work computer. My desk and computer are viewable to all people who enter the office as well as those that work within the office. If you are at any type of angle looking at my computer, the privacy screen works great. All you will see is a black screen. If you are behind the computer you can see everything no matter how far away you are. I wish that it remained a black screen unless you were sitting directly in front of it but if you are anywhere behind the computer at any distance you can still see everything. It only blacks out when you are at an angle. It was very easy to install and serves the purpose for which it was purchased. I would recommend this product.